Motion overshoot suppression control method for pintle type fast-response gas valve

Abstract

The invention provides a motion overshoot suppression control method for a pintle type fast-response gas valve, which adopts a three-ring nested control mode of valve core position-motor rotating speed-motor phase current, improves the response speed and the anti-interference capability in the acceleration and deceleration process of a motor by controlling the phase current, improves the speed regulation performance by a speed ring, and improves the stability of the motor. Finally, accurate following of the target position of the valve element is achieved through the position control ring, and zero-static-error control can be achieved. According to the motion overshoot suppression control method for the pintle type fast-response gas valve, motion overshoot of the valve element is effectively suppressed, disturbance of pneumatic load changes is resisted, and it is verified that the control overshoot amount is smaller than 2% when the valve element is loaded.

Description

Technical Field

[0001] The invention relates to a throat-plug type fast-response gas valve motion overshoot suppression control method, belonging to the technical field of solid attitude and orbit control rocket engines. Background Art

[0002] The throat plug type solid attitude and orbit control engine has many advantages of solid rocket engine, such as simple structure and easy storage. At the same time, it can realize continuous adjustment of thrust, and can perform attitude stability control and flight trajectory adjustment according to the flight state of the missile, becoming an important direct force control device of the weapon system. The thrust adjustment response of the missile is required to be fast during flight, but the motor servo mechanism is constrained by the quality conditions, and the driving power margin is relatively small. In addition, the valve core is affected by the high-speed airflow and aerodynamic load, and the load of the valve core changes at different opening positions. Therefore, when the valve core moves rapidly in a step, a large overshoot is likely to occur, which affects the thrust stability and thrust adjustment accuracy of the attitude and orbit control engine. Based on the three-loop nested control of the valve core mechanism position, motor speed, and motor current, the position deviation rate is introduced to distinguish the position target value. When the target position changes rapidly, the motion trajectory of the speed loop is planned and designed, and the position deviation is directly introduced into the current control loop to speed up the current response and overcome the disturbance caused by the load change, thereby ensuring the response speed while enhancing the anti-disturbance ability and reducing the position overshoot.

[0003] At present, the following problems exist in the motion control of the throat plug type fast response gas regulating valve:

[0004] 1. The power margin of the motor servo drive is small. The attitude and orbit control engine is limited by the structural quality, and the margin is small when the servo drive is selected and designed. It usually works under short-term overload, and the control stability of the valve core during movement is poor.

[0005] 2. The load of the valve core movement changes greatly. When the valve core moves backward and the valve is opened, the pneumatic pressure at the head of the valve core is higher to help the valve core move. When the valve core moves forward and the valve is closed, the pressure at the head of the valve core decreases and the pressure at the tail is higher. The pneumatic force direction changes and still helps the valve core move in the same direction of movement. It has positive feedback disturbance characteristics, which makes the control system tend to diverge.

[0006] 3. The servo mechanism has small inertia and high dynamic response requirements. In order to meet the rapid response of thrust adjustment, the valve core movement requires high dynamics. The reduction ratio of the servo motor is relatively small, the system inertia is small, and the load change has a great impact on the stability of the motor. It is difficult to balance rapidity and stability. Overshoot and control instability are prone to occur under load disturbance. Summary of the invention

[0007] The problem solved by the present invention is: in view of the problems of large overshoot of valve core position control and poor control stability during rapid thrust adjustment of a throat-bolt type solid attitude and orbit control engine, a throat-bolt type gas valve motion overshoot suppression control method is proposed. The motor speed loop can be motion planned according to the change of the valve core position deviation rate, the current response can be accelerated to resist load disturbance, the valve core position overshoot suppression can be achieved, the anti-disturbance ability of the control system can be enhanced, and the position overshoot can be suppressed while ensuring the requirement of motion rapidity.

[0008] The technical solution provided by the present invention is: a throat plug type fast response gas valve motion overshoot suppression control method, characterized in that it comprises the following steps:

[0009] (1) Design the motor phase current control link:

[0010] According to the rated working current, overload capacity and torque coefficient of the motor, considering the workload and starting response time requirements, set the maximum instantaneous drive current allowed during the motor operation process, select the corresponding current sensor, and use the deviation value between the current target value and the current sensor test value as the input of the current feedback controller;

[0011] (2) Design the motor speed control link:

[0012] According to the motor rated speed, reduction ratio and response time requirements, the maximum operating speed of the motor is set, the corresponding speed sensor is selected, and the deviation between the speed target and the speed sensor feedback is used as the input of the speed controller. The output of the speed controller is the current target, completing the nesting of the speed loop and the current loop.

[0013] (3) Design of valve core position control loop:

[0014] 31) Given the target position of the valve core adjustment, collect the current valve core position fed back by the position sensor, calculate the position deviation Δx, perform differential operation on the position deviation, and obtain the position deviation rate

[0015] 32) Design the position deviation rate threshold value according to the position adjustment frequency response requirements

[0016] 33) Compare position deviation rate Threshold like Then the position deviation Δx is used as the input of the position controller, and the speed loop target value is directly output after the controller calculation, such as Then the motion planning design of the speed loop target value is carried out to avoid excessive speed instructions, which will cause the motor to have difficulty in decelerating in a short time after the valve core is in place and cause overshoot;

[0017] 34) When When the position deviation Δx is proportionally calculated and directly used as part of the current loop target value, the current control is quickly started to overcome the load disturbance, while achieving fast response and no overshoot control.

[0018] Preferably, the motion control structure is based on a three-loop nested approach of valve core position, motor speed, and motor phase current;

[0019] Preferably, the speed loop target value is planned and designed according to the position loop deviation change rate;

[0020] Preferably, for a rapidly changing position loop target value, the position deviation is directly used as a partial target value of the current loop after proportional calculation;

[0021] Preferably, according to the frequency response requirement of the valve core regulating movement, a position change rate threshold is designed to determine whether the valve core position is a smooth and continuous movement.

[0022] Preferably, according to the valve drive load, motor rated power and overload capacity, the maximum instantaneous drive current allowed during the motor operation is set as the command peak of the current control loop, and the current loop control bandwidth is designed, usually 20kHz, and two current sensors with high-frequency response characteristics are selected to measure the motor A phase and B phase currents respectively;

[0023] Preferably, the maximum position deviation rate of the valve is designed according to the command cycle requirement of the valve position adjustment and the maximum change rate of the position target value. When the position deviation rate is greater than The speed loop is motion planned at this time. According to the motor speed regulation capability and position deviation rate, the speed loop target quantity is planned in triangle or trapezoidal way. The purpose is to ensure that when the valve core is in place, the motor deceleration process can better follow the speed target quantity change and realize motion overshoot suppression.

[0024] Preferably, the valve core mechanism position control loop and the motor speed control loop use the same control cycle, and position deviation rate comparison, speed loop target value planning and judgment, speed planning and design, etc. are completed in each control cycle. When the motor rotates at a constant speed, the valve core mechanism moves at a constant speed, the position loop sensor feeds back the valve core position signal, and the encoder feeds back the angular displacement increment of the motor rotation, which is divided by the speed loop control cycle to obtain the motor speed.

[0025] Preferably, considering the influence of the reducer and transmission mechanism, the relationship between the motor speed and the valve core movement rate is established, and the maximum working speed v of the motor is designed according to the motor rated speed and the valve core adjustment response time requirements. max During the movement of the valve core mechanism, when the motor speed target value calculated by the position loop controller exceeds the maximum working speed, the trapezoidal instruction is used to plan the speed loop target value. When the motor speed target value is less than the maximum working speed, the triangle instruction planning method is used.

[0026] Preferably, the speed loop target value planning aims to artificially slow down the rate of change of the speed target value during the high-dynamic acceleration and deceleration process of the motor, to ensure that when the valve core is in place, the motor deceleration process can better follow the change of the speed target value, to avoid the motor speed deviation caused by load changes when the mechanism moves rapidly, and to suppress the position overshoot.

[0027] Preferably, a current saturation output is set, and when the motor speed continuously deviates from the target value or the current compensation amount given by the position loop is too large, the current loop controller has a saturation current limiting capability to prevent damage to the motor and the current sensor.

[0028] The advantages of the present invention compared with the prior art are:

[0029] (1) A throat-type fast-response gas valve motion overshoot suppression control method in the present invention can realize the design planning of the motor speed control loop, limit the rate of change of the speed target value during the dynamic acceleration and deceleration process of the motor, and ensure the followability of the motor speed. When the valve core moves into place, the speed loop target value decreases to zero, the actual motor speed is also zero, and the mechanism stops moving to achieve zero-overshoot control.

[0030] (2) In the present invention, when the motor performs dynamic acceleration and deceleration against the valve core load, the position deviation rate is compensated to the current loop target value, bypassing the speed loop to speed up the provision of the current target value, and improving the current response before the valve core is accelerated, thereby ensuring the mechanical characteristic stiffness of the motion control system, improving the valve core adjustment response speed and taking into account the anti-interference ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 (a) is a schematic diagram of the triangle speed target value planning in the present invention, Figure 1 (b) The measured effect of triangle planning. Figure 2 (a) is a schematic diagram of trapezoidal speed target value planning in the present invention, Figure 2 (b) The measured effect of trapezoidal planning, Figure 3 It is a flow chart of the control method in the present invention. DETAILED DESCRIPTION

[0032] A throat plug type fast response gas valve motion overshoot suppression control method in the present invention will be further described in detail below with reference to the accompanying drawings.

[0033] The present invention provides a throat plug type fast response gas valve motion overshoot suppression control method, the control method comprises the following implementation steps:

[0034] Step 1: Current control loop design;

[0035] The characteristics are as follows: the maximum instantaneous drive current allowed during the operation of the motor is set; when the current loop output is saturated, the motor is started at the maximum power; the current loop control bandwidth is designed; 20kHz is selected as the empirical value; two current sensors with high-frequency response characteristics are selected to measure the motor A-phase and B-phase currents respectively; and the current control can adopt proportional-integral control.

[0036] Step 2: Speed ​​Control Loop Design:

[0037] 21) Speed ​​calculation and fluctuation deviation design

[0038] According to one embodiment of the present invention, the motor speed is calculated by dividing the angular displacement increment sampled by the encoder within two control cycles by the control cycle. The allowable speed fluctuation is designed to prevent the fluctuation of the angular displacement sampling from affecting the speed control. When the deviation between the measured speed and the target speed is greater than the allowable fluctuation, the speed control is performed with the measured speed as the feedback. The speed loop control bandwidth is designed, and 4kHz is selected as the empirical value. Proportional integral control can be used.

[0039] 22) Maximum operating speed and maximum acceleration process planning

[0040] When the position deviation rate is greater than the critical value When the motor speed and acceleration process are motion planned.

[0041] According to one embodiment of the present invention, the maximum operating speed v of the motor is designed max For small servo motors with high speed and good starting performance, the reference value is 0.5 to 0.7 times the rated no-load speed. For slow motors with lower rated speed, the reference value is 0.7 to 0.9 times the rated no-load speed.

[0042] The characteristics are as follows: the speed loop target value is planned according to the uniform acceleration process, the acceleration time t is 0.15 to 0.2 times the step response time, and the maximum working speed v max and acceleration time t to obtain the maximum acceleration a max , the motor is a max Perform uniform acceleration motion, the position loop deviation is directly compensated to the current loop, the current loop positive output is saturated, sufficient acceleration current is provided, and the motor accelerates at its maximum capacity under the current load conditions. When the motor speed target value calculated by the position loop controller exceeds the maximum operating speed v max When the motor speed target value maintains the maximum value v max , until the speed target value calculated by the position loop controller is less than the maximum operating speed v max , the speed loop desaturates, the current loop reverses and outputs to provide braking current, and the motor starts to decelerate, that is, the trapezoidal programming method is adopted.

[0043] According to one embodiment of the present invention, when the motor speed target value calculated by the position loop controller fails to reach the maximum operating speed v max When the motor is a max Perform uniform acceleration motion, and enter the deceleration state after the measured speed reaches the calculated speed, that is, the triangle planning method is adopted. Through the speed target value planning, the maximum speed of the motor is limited and there is sufficient deceleration time, which can ensure that when the valve core position approaches the target position, the actual motor speed gradually decreases to zero following the change of the target value, that is, the speed control is zero when the valve core moves to the right position, thereby realizing the position without overshoot control.

[0044] Step 3: Position control loop design:

[0045] 31) Given the target position of the valve core adjustment, collect the current valve core position fed back by the position sensor, calculate the position deviation Δx, perform differential operation on the position deviation, and obtain the position deviation rate

[0046] 32) Design the position deviation rate limit value according to the position adjustment response time and maximum stroke requirements

[0047] 33) Compare position deviation rate Threshold when When the valve core is considered to be in smooth continuous motion, the speed target value is not designed and planned, and the position deviation Δx is used as the input of the position controller. After the controller calculates, the speed loop target value is output, and the process is carried out as described in step (21); when When the valve core is considered to be in a rapid step motion, the speed loop target value is subjected to the motion planning design described in step (22) to avoid a large deviation between the speed target value and the actual speed, which may cause deceleration difficulties and overshoot;

[0048] 34) When When the position deviation Δx is proportionally calculated and directly used as part of the current loop target value, the current control is quickly started to overcome the load disturbance, while achieving fast response and no overshoot control.

[0049] A throat-plug-type fast-response gas valve motion overshoot suppression control method proposed in the present invention compares the response processes of the valve core during full-stroke and half-stroke rapid step motions, and can achieve zero-overshoot control when the valve core is disturbed by load, thereby ensuring the valve motion response speed while effectively suppressing the step response overshoot caused by load changes.

Claims

1. A throat plug type fast response gas valve motion overshoot suppression control method, characterized in that: The following steps are involved: Step 1: Design motor phase current control; Step 2: Design the motor speed control; Step 3: Design the spool position control.

2. A throat plug type fast response gas valve motion overshoot suppression control method according to claim 1, characterized in that: Step 1 includes: according to the rated working current, overload capacity and torque coefficient of the motor, considering the workload and starting response time requirements, setting the maximum instantaneous drive current allowed during the operation of the motor, selecting the corresponding current sensor, and taking the deviation value between the current target value and the current sensor test value as the input of the current feedback controller.

3. A throat plug type fast response gas valve motion overshoot suppression control method according to claim 2, characterized in that: Step 2 includes: setting the maximum operating speed of the motor according to the rated speed, reduction ratio and response time requirements of the motor, selecting the corresponding speed sensor, and taking the deviation value between the speed target and the speed sensor feedback as the input of the speed controller. The output of the speed controller is the current target, thus completing the nesting of the speed loop and the current loop.

4. A throat plug type fast response gas valve motion overshoot suppression control method according to claim 3, characterized in that: Step 3 includes: Step 31) Given the target position of the valve core adjustment, collect the current valve core position fed back by the position sensor, calculate the position deviation Δx, perform differential operation on the position deviation, and obtain the position deviation rate Step 32) Design the position deviation rate threshold value according to the position adjustment frequency response requirements Step 33) Compare the position deviation rate Threshold like The position deviation Δx is used as the input of the position controller, and the speed loop target value is directly output after the controller calculation. Then the motion planning design of the speed loop target value is carried out to avoid excessive speed instructions, which will cause the motor to have difficulty in decelerating in a short time after the valve core is in place and cause overshoot; Step 34) When When the position deviation Δx is proportionally calculated and directly used as part of the current loop target value, the current control is quickly started to overcome the load disturbance, while achieving fast response and no overshoot control.

5. The throat plug type fast response gas valve motion overshoot suppression control method according to claim 1, characterized in that: The control method is aimed at the movement control of the valve core of an electrically adjustable gas valve, and adopts a three-loop nested control mode of valve core position, motor speed, and motor phase current.

6. A throat plug type fast response gas valve motion overshoot suppression control method according to claim 2, characterized in that: The speed loop target value is planned and designed according to the position loop deviation change rate.

7. A throat plug type fast response gas valve motion overshoot suppression control method according to claim 6, characterized in that: For the rapidly changing position loop target value, the position deviation is directly used as part of the current loop target value after proportional operation.

8. A throat plug type fast response gas valve motion overshoot suppression control method according to claim 7, characterized in that: According to the frequency response requirements of the valve core adjustment movement, the position change rate threshold is designed to determine whether the valve core position is smooth and continuous movement.

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